Folding apparatus for web-fed rotary printing presses

ABSTRACT

A folding apparatus for web-fed rotating printing presses which comprises a machine wall, folding knives, and one movable folding blade. A fixed folding blade stop is provided. One movable folding blade, operating against the fixed folding blade stop, coordinated to each of the folding knives. A folding knife cylinder, and two double-armed levers. The folding knives are guided under taut spring action and disposed on one of the double levers. One of the levers has a cam roller, which engages temporarily for the duration of the rearward movement of the cylinder a swingable cam segment. A hub is provided and a cam is fastened to the hub and has two surfaces extending at an obtuse angle to each other, and is adapted for fixing the position of the cam segment. A switch for the blocking of a control circuit for at least one of the forward and rearward movements of the folding apparatus is controlled by the cam.

United States Patent Hertrich FOLDING APPARATUS FOR WEB-FED ROTARY PRINTING PRESSES [75] Inventor: Klaus Hertrich, Gohrenz, Germany [73] Assignee: VEB Polygraph Leipzig, Kombinat fuer polygraphische Maschinen u. Ausruestungen, Leipzig, Germany [22] Filed: Jan. 27, 1971 [21] Appl. No.: 110,050

[56] References Cited UNITED STATES PATENTS 2,797,084 6/1957 Hilgoe. .f. 270/43 2,819,068 1/1958 Loase 270/73 In] 3,787,042 5] Jan. 22, 1974 Primary Examiner-Robert Michell Attorney, Agent, or Firm-Ernest G. Montague [57] ABSTRACT A folding apparatus for web-fed rotating printing presses which comprises a machine wall, folding knives, and one movable folding blade. A fixed folding blade stop is provided. One movable folding blade, operating against the fixed folding blade stop, coordinated to each of the folding knives. A folding knife cylinder, and two double-armed levers. The folding knives are guided under taut spring action and disposed on one of the double levers. One of the levers has a cam roller, which engages temporarily for the duration of the rearward movement of the cylinder a swingable cam segment. A hub is provided and a cam is fastened to the hub and has two surfaces extending at an obtuse angle to eachother, and is adapted for fixing the position of the cam segment. A switch for the blocking of a control'circuit for at least one of the forward and rearward movements of the folding appa- PATENTED JANZ 21974 SHEET 1 0F 2 INVENTOR KLAUS HERTERICH ATTORNEY.

PATENTEDJANZZW 3'. 787, 042

sum 2 or 2 INVENTOR BYK US HERTERICH ATTOR EY.

FOLDING APPARATUS FOR WEB-FED ROTARY PRINTING PRESSES The present invention relates to a folding apparatus for web-fed rotary printing presses in which only one folding blade operating against a fixed folding blade stop is associated with each folding knife.

In a number of known rotating folding apparatus each of the folding cylinders operates with two movable folding blades each. In this way, the advantage is obtained, that upon the rearward movement of the unit, the folding knife can be moved between two folding blades in exactly the same manner as upon forward operation. This embodiment has the disadvantage, that due to wear and preexisting bearing play in both folding blades, relatively large sources of error result. Improperly folded products are then the consequence. For this reason one is going over more and more to devices, in which a movable folding blade cooperates with a rigid folding blade stop. In this case, however, difficulties arise, if for any reason, for instance as a result of stoppers, rearward movement of the folding cylinders becomes necessary. In such a case, as soon as the folding knife cylinder in reverse travel remains, even only a small amount behind the folding blade cylinder as a result of normal tooth clearance or the like, there is the danger that the folding knife will strike against the fixed folding blade stop and be damaged. This has been remedied by omitting the returntravel in its entirety and in the manner, that if return travel is indispensable, the manufacturer recommends that the folding knives be removed.

Now, however, in rotating folders, which are directly connected with web-fed rotating printing presses, there arises the necessity of effecting rearward travel for various and particularly purely technological reasons, namely upon the introduction of the printing'plates or 7 rubber blankets, for instance, of a web-fed rotating offset printing press. For this operation the folding apparatus could, to be sure, be disconnected. Since in particular the reconnecting of the folding machine is very time consuming, it is not desirable to do so. Some known embodiments nevertheless require the disconnecting of the folding machine and offer the user, in order to save time, an automatic, relatively expensive coupling device. Another case in which the rearward movement of the cylinders of the folding machine is necessary results for reasons of'protection of the workers. If, for instance, due tocarelessness an article of clothing or the like should be caught, immediate rearward travel is necessary, and in such case, if immediate assistance is necessary, it wouldbe impossible then first of all to remove the folding knives.

From German Patent No. 257,644 there are known devices in connection with which the folding knife is v guided by fingers arranged on the folding bladebetween the folding blade and the folding blade stop even upon the rearward rotation of the machine. At high speeds, however, there is an intolerable amount of noise and extensive wear due to the sliding of the parts on each other, so that use thereof does not enter into consideration in the case of highspeed machines.

In accordance with German Pat. No. 633 756, it is already known to make the folding knives movable, i.e., retractable to within the periphery of the folding knife cylinder. In this case, however, the same problem arises as in all other controlled folding knife movements. The control is effected byv cams, which move uniformly corresponding 'to the speed of the folding knife cylinder. As a result, the folding knives carry out the same movements upon rearward as upon normal operation. In this case also, we have the result that upon rearward travel the folding knife can strike against the folding blade stop.

It is one object of the presentinvention to provide a folding apparatus for web-fed rotary printing presses, wherein the disadvantages of the prior art structures are avoided.

It is another object of the present invention to provide a folding apparatus, in which a separating of the folding apparatus from the printing press during the rearward travel is unnecessary, but in which, however, on the other hand, assurance can be definitely had, that the folding knife will not strike against the folding blade stop.

It is still another object of the present invention to provide a folding apparatus for web-fed rotary printing presses, wherein it is possible for the operators to start the rearward movement without any great mental effort.

It is yet a still further object of the present invention 7 to provide a folding apparatus for web-fed rotary printing presses, wherein the folding knife is adjustably guided under taut spring action in the folding knife cylinder and is arranged on a double-armed lever and a simple lever for swinging about a shaft, the doublearmed lever having a cam roller which, for the duration of the rearward movement of the cylinder of the folding apparatus, moves temporarily on an inwardly swingable cam segment. On a hub equipped with two surfaces extending at an obtuse angle to each other there is fastened acam, by which a switch for the locking of the control current for the forward and/or rearward movement of the folding apparatuscan be actuated. The mentioned surfaces, which extend at an obtuse angle to each other are provided for the fixing of the position of the cam segment, and one of the surfaces is further from the center of the hub than the other. In accordance with another feature of the present invention, the cam segment is connected firmly with a swingable lever, which is supported swingably on the inner side of the machine wall and can be brought by a tension spring against a respective one of the mentioned surfaces of the hub. The hub, which bears the mentioned surfaces can be moved radiallyin its position by a hydraulically or pneumatically actuatable working cylinder or else by hand by means. of a shifting lever.

With these and other objects in view which will become apparent in the following detailed description, the present invention, which is shown by example only, will be clearly understood inconnection with the accompanying drawings, in which:

FIG. 1 is a front elevation, partly in section, of th folding knife cylinder;

FIG. 2 is a section along the lines 2-2 of FIG. 1, shown in a position of the folding knife which corresponds to the forward or operating movement of the cylinder; and

FIG. 3 is a view similar to that of FIG. 2, but in a position, as the folding knife assumes in the range of the folding blade cylinderduring the rearward movement of the cylinder.

Referring now to the drawings in the folding knife cylinder 1 is supported a shaft 2, around which, on levers 3 and 3, the knife beam 4 is turnable between stops or abutments and compression springs 6. Alongside the lever 3, there is also firmly connected to the shaft 2 a swing lever 7 on the end of which a cam roller 8 is provided. The lever 3 and the swing lever 7 can also be developed as double-armed levers. The folding knife 9 is guided by a plurality of screws 10 and is pressed by compression springs 11 against the knife beam 4 The stops 5 of the knife beam 4 each come against an adjustable screw 12 by which the operating height of the folding knife 9 can be adjusted against the pressure of the compression springs 6. The compression springs 6 can also be adjusted by means of screws 13, in order to establish a minimum force. A lever 16 is pivoted to the inside of the machine wall 14 by a bolt 15, the lever resting on a hub 17 loosely arranged on the folding knife cylinder shaft 1, hub having two detent surfaces 18 and 19 arranged at an obtuse angle to each other. The surface 18 is a specific distance further from the center of the hub 17 than the surface 19. A tension spring 20 provides that the lever 16 is pressed firmly against one each of the surfaces 18 or 19. On the lever 16, there is rigidly arranged via a spacer 21 a cam segment 22 which, with the aid of the surfaces 18 and 19 of different heights, passes, when the lever 16 rests on the surface 18, into the range of the cam roller 8 or, by the sitting of the lever 16 on the surface 19, is swung out of the region of the cam roller 8.

On the hub 17 there is furthermore provided a cam 23 by which a spring biased switch rod 24 of a changeover switch 25 can be brought into three different switch positions; the rod 24 sits directly on the periphery of the hub 17, when the latter has been so turned, for instance by the actuation of a shifting lever 26, that the lever 16 rests on the surface 18. The shifting lever 26 of the hub 17 is guided in a curved longitudinal slot not shown of corresponding radius of curvature not shown in the drawing. During the rotation of the hub 17, the rod 24 is brought by the lower surface 23' of the cam 23 into a position between the contact pairs 27 and 28 and the contact pair 28 is closed only when the high surface 23" of the cam 23 is reached, and therefore when the lever 16 rests fully on the surface 19. While with the closing of the contact pair 28 the control current for the rearward movement of the cylinder is blocked in known manner (FIG. 2), upon the closing of the contact 27 the forward travel is also electrically blocked in known manner (FIG. 3). By the lower surface 23' of the cam 23, assurance is had that an incomplete change in the position of the hub 17 cannot lead to damage. As long as the switch rod 24 is not resting either against the hub 17 or against the high cam surface 23", both control currents, namely that for forward travel and that for rearward travel, are blocked.

By means of the arrangements on the folding apparatus, in accordance with the present invention, it is possible readily to permit rearward movements of the cylinder in the manner, for instance, that the hub 17 is turned merely by means of the switch lever 26 in such a manner, that the lever 16 rests on the surface 18. In this way the folding knife 9, as long as it passes through the range of the folding-blades and -stops, is pulled by the movement of the cam roller 8 onto the cam segment 22 via levers 3 and 7 to such an extent below the outer surface of the folding knife cylinder 1, that mutual contact is absolutely prevented during the rearward travel.

The changing of the position of the hub 17 can be effected manually. However, it isalso possible to change the position of the hub 17 automatically by means of a hydraulic or pneumatic work cylinder in the manner, that the control of the latter'is effected as a function of the instantaneous connecting process for the normal forward and rearward movement of the folding cylinder.

While I have disclosed one embodiment of the present invention, it is to be understood, that this embodiment is given by example only and not in a limiting sense.

I claim:

1. A folding apparatus for web-fed rotating printing presses comprising a machine wall,

a folding knife cylinder mounted for rotation about an axis,

a folding blade stop mounted in said cylinder,

a first lever movably connected to said cylinder,

a folding knife including a movable folding blade and disposed on said first lever, and said folding blade operatively moving against said stop,

spring means for guiding said folding knife under taut spring action,

a second lever operatively connected to said first lever and having a free end,

a cam roller mounted on'said free end of said second lever,

a cam segment operatively pivotally connected to said machine wall,

said cam roller disposed adjacent said cam segment,

a rotatable hub rotatably mounted with respect to said machine wall and rotatable relative to said cylinder and about an axis which is substantially coinciding with the axis of said cylinder and having two peripheral surfaces extending at an obtuse angle to each other and operatively abutting selectively against said two surfaces of said cam segment, for changing the position thereof dependent upon the position of said hub,

a cam fastened to said hub, and

a switch means operatively disposed against said cam and controlled thereby for stopping at least one of the forward and rearward movements of said cylinder, dependent upon the position of said hub, and

said two surfaces having different distances from a center of said hub, respectively such that at one rotated position of said hub, one of said two surfaces operatively moves said cam segment into movable engagement against said cam roller.

2. The folding apparatus, as set forth in claim 1, further comprising a third lever swingably mounted to an inside of said machine wall,

said cam segment being rigidly connected to said third lever, and

a tension spring means for pressing said third lever into engagement with one of said surfaces of said hub.

3. The apparatus, as set forth prising a shaft disposed in said cylinder,

said first and second levers are connected to said shaft, and means for turning said hub.

in claim 1, further com- 

1. A folding apparatus for web-fed rotating printing presses comprising a machine wall, a folding knife cylinder mounted for rotation about an axis, a folding blade stop mounted in said cylinder, a first lever movably connected to said cylinder, a folding knife including a movable folding blade and disposed on said first lever, and said folding blade operatively moving against said stop, spring means for guiding said folding knife under taut spring action, a second lever operatively connected to said first lever and having a free end, a cam roller mounted on said free end of said second lever, a cam segment operatively pivotally connected to said machine wall, said cam roller disposed adjacent said cam segment, a rotatable hub rotatably mounted with respect to said machine wall and rotatable relative to said cylinder and about an axis which is substantially coinciding with the axis of said cylinder and having two peripheral surfaces extending at an obtuse angle to each other and operatively abutting selectively against said two surfaces of said cam segment, for changing the position thereof dependent upon the position of said hub, a cam fastened to said hub, and a switch means operatively disposed against said cam and controlled thereby for stopping at least one of the forward and rearward movements of said cylinder, dependent upon the position of said hub, and said two surfaces having different distances from a center of said hub, respectively such that at one rotated position of said hub, one of said two surfaces operatively moves said cam segment into movable engagement against said cam roller.
 2. The folding apparatus, as set forth in claim 1, further comprising a third lever swingably mounted to an inside of said machine wall, said cam segment being rigidly connected to said third lever, and a tension spring means for pressing said third lever into engagement with one of said surfaces of said hub.
 3. The apparatus, as set forth in claim 1, further comprising a shaft disposed in said cylinder, said first and second levers are connected to said shaft, and means for turning said hub. 